In one type of duct forming machine, strip material is fed to a mandrel to encapsulate a helical coil of reinforcing wire. The overlapping edges of the strip material are sealed with glue to form a flexible duct core for use in assemblying heating and cooling flexible duct. The flexible strip material has a width of only a few inches with the overlap being substantially less than an inch. It is imperative that this overlap of strip material be properly aligned so that the bonding and encapsulation of the reinforcing wire coil is secure. If the strip material being fed is out of alignment, wrinkles or bubbles can form along the overlapping edges preventing a positive seal.
An additional problem is presented by the strip material being fed from a large spool of material in which misalignments are magnified as the supply reel becomes smaller in diameter. The spool is initially properly aligned so that the strip material is nearly in a horizontal plane when being fed. As the spool diameter decreases, the strip material will be at an increasingly downard angle which can cause problems of alignment as well as glue application.
Therefore it would advantageous if misalignments could be compensated for by accurately readjusting the spool from time to time to prevent improper seals around the reinforcing wire. To insure an efficient smooth seal any adjustment should permit vertical, horizontal as well as angular adjustments to provide proper alignment. Vertical adjustment compensates for the diminishing size of the supply spool.
It is therefore one object of the present invention to provide a duct forming machine having a strip material feed system which has vertical adjustment.
Yet another object of the present invention is to provide a duct forming machine having a strip material feed system having microadjustment control for vertical, horizontal and angular alignment.